Gas cupola furnace with gas distribution ridge



March 10, 1970 A E m. 3,499,637

GAS CUPOLA FURNACE WITH GAS DISTRIBUTION RIDGE Filed. April 6, 1967 FIE 3' 4 o o I I I I 00 0 0 0 0 0 o o o o o 0 0 0 0000 0 0 0 0a 0 a o 0 0 a Q 0 0o 0 I a a 0 0 p d g a a M220 United States Patent US. Cl. 266-25 4 Claims ABSTRACT OF THE DISCLOSURE A lower shoulder in the shaft of a cupola furnace is provided with an upstanding central ridge extending from the aperture, formed between the lower shoulder and a spaced upper shoulder, to the opposite wall of the shaft. The material charged into the furnace is divided by the ridge and passes through the space between the shoulders into the shaft below the lower shoulder where superheating takes place, the ridge ensuring uniform gas distribution over the section of the shaft and preventing formation of a metal sow on the lower shoulder.

The present invention relates to the field of metallurgy, and more particularly to gas cupola furnaces for melting metal.

Known in the prior art is a gas cupola furnace, constructed according to the Soviet Authors Certificate No. 167,613, Class 31a, l/01. The medium part of the shaft of this cupola furnace is provided with two shoulders: the lower one for maintaining the column of charge materials and the upper one for preventing the charge from falling into the lower part of the cupola furnace shaft or its superheating chamber. The melting and superheating of metal are effected in the cupola furnace shaft when burning a gaseous fuel in its lower part. This cupola furnace lends itself to the making of molten metal heated to a temperature sufiicient for casting thin walled parts.

The production capacity of the gas cupola furnace is thereby higher than that of a coke cupola furnace of the same size, being more simple as to its design and occupying a smaller floor space.

When melting pig iron in this cupola furnace, however, a metal sow is formed on the bottom of the lower shoulder, resulting from a non-uniform distribution of gases throughout the shaft cross-sectional area. This is likely to decrease the metal temperature, the production capacity of the cupola furnace, and complicate its repairing after melting.

It is an object of the present invention to eliminate the above-said disadvantages. Other objects and advantages of the invention will become more fully apparent from the following description.

The principal object of the present invention is to provide a gas cupola furnace which lends itself to the melting of pig iron without the formation of the metal sow on the bottom of the lower shoulder.

This object is achieved by a gas cupola furnace having in its shaft, shoulders for maintaining the charge materials and for preventing the charge from falling directly into the superheating chamber, and wherein on the bottom of the lower shoulder, in its median portion, there is provided a ridge of refractory material extending in the direction from the space between the shoulders towards the opposite side of the shaft wall in the internal cavity of the shaft.

The invention will be described further, by way of example, with reference to the accompanying drawing, in which:

FIG. 1 is a longitudinal section of the cupola furnace constructed in accordance to the invention;

FIG. 2 is a cross-sectional view taken on the line IIII of FIG. 1; and

FIG. 3 is a cross-sectional view taken on the line IH- III of FIG. 2.

The gas cupola furnace is provided in its shaft with two shoulders: a lower one 1 (FIG. 1) for supporting the column of charge materials, and an upper one 2 for preventing the charge from falling directly into the lower part of the cupola furnace shaft i.e. the chamber for superheating the metal. Disposed in the median portion of the shaft, the shoulders are fitted with pipes 3 and 4 for water cooling. Provided in the lower part of the shaft is a bottom 5 made with a depression in the form of a well 6 intended for accumulating metal to be superheated. Provided directly over the metal surface in the well is an outlet hole of a tunnel 7, for burning the gas-air mixture supplied from a tuyere.

Provided on the bottom of the lower shoulder is a division ridge 8 of refractory materials having a somewhat greater height than the distance between the shoulders. A semi-circular internal cavity 9 is formed above the bottom of the lower shoulder (FIG. 2). The ridge 8 is designed to divide the space of the widened part between the shoulders into two zones. A certain gap is provided between the end of the division ridge and the wall of the widened part for allowing an annular flow of gases.

The gas cupola furnace operates in the following manner. A charge consisting of metal and fluxes is loaded into the cupola furnace shaft. Gas and air are supplied into tuyeres thereby being intermixed. The gas-air mixture thus obtained is burned in the tunnel. The products of combustion are directed into the cupola furnace shaft, and metal is melted thereby. The molten metal drops from the lower shoulder into the well provided on the bottom of the superheating chamber.

Because the division ridge is disposed on the .bottom of the lower shoulder, the gases are distributed uniformly throughout the shaft cross section, thus precluding the formation of the metal sow on the bottom and contributing to the superheating of metal and increasing the production capacity of the cupola furnace.

Through the present invention is described in conjunction with its preferred exemplary embodiment, it is evident that there may be allowed modifications and variants thereof that do not depart from the idea and scope of the invention, which willbe readily understood by those skilled in the art.

What is claimed is:

1. A gas cupola furnace comprising a vertical shaft, a lower shoulder in said shaft for supporting a column of charged material, an upper shoulder arranged above the lower shoulder to prevent the charge from falling directly into the shaft, said upper shoulder being spaced above the lower shoulder and defining therewith an opening for passage of the charged material into the shaft below the lower shoulder, and a ridge of refractory material on the lower shoulder extending from said opening in a direction away therefrom and having a height which is greater than the spacing between the shoulders said ridge being substantially centrally disposed on said lower shoulder.

2. A furnace as claimed in claim 1 wherein said shaft has an upright internal cavity for the charged material above said lower shoulder, said ridge dividing said cavity at the lower shoulder.

3. A furnace as claimed in claim 2 wherein said cavity is semi-circular, and said extends diametrically across said cavity into spaced relation with the shaft atthe internal surface thereof opposite said opening.

3 4 4. A furnace as claimed in claim 1, wherein said lower 3,285,590 11/1966 Parsons 26329 shoulder and said ridge slope downwardly towards said 1,329,055 1/1920 Jakova-Merturi 266-29 X opening between the shoulders.

ROBERT D. BALDWIN, Primary Examiner References Cited UNITED STATES PATENTS 5 2,238,516 4/1941 Chatterton 263-29 X 2,667,342 1/1954 Eller beck 26329 

